摘要
在63只切断两侧缓冲神经的麻醉sprague-Dawley大鼠,应用细胞外记录的电生理学方法,观察颈内动脉注射肾上腺髓质素(adrenomedullin,AM)对最后区(area postrema,AP)神经元自发电活动的影响。实验结果如下:(1)在记录到的78个自发放电单位中,颈内动脉内注射AM(0.3 nmol/kg),引起其中47个单位的自发放电频率由2.99±0.24增加到4.79±0.29 spikes/s(P<0.001),20个单位自发放电频率由3.24±0.46下降至1.97±0.37 spikes/s(P<0.001),另外11个单位自发放电频率无明显改变;平均动脉压和心率无明显变化。(2)颈内动脉注射降钙素基因相关肽受体阻断剂CGRP_(8-37)(3 nmol/kg)不能改变AM对自发放电的兴奋效应;(3)颈内动脉注射L-精氨酸(30 mg/kg)可减弱AM对自发放电的兴奋效应。以上结果提示,AM对最后区神经元有兴奋作用,此作用不是由降钙素基因相关肽受体介导,但可被NO前体L-精氨酸所减弱。
To observe the effect of intracarotid administration of adrenomedullin (AM) on the spontaneous electrical activity of area postrema (AP) neurons, 78 spontaneous active units were recorded from 63 sino-aortic denervated Sprague-Dawley rats using extracellular recording technique. The results obtained are as follows. (1) Following intracarotid administration of AM (0.3 nmol/kg), the discharge rate of 47 out of 78 units increased markedly from 2.99±0.24 to 4.79±0.29 spikes/s (P<0.001), 20 units decreased from 3.24+0.46 to 1.97±0.37 spikes/s (P<0.001), and the remaining 11 showed no response.Blood pressure (BP) and heart rate (HR) did not change throughout the experimentation. (2) Pretreatment with intracarotid administration of caleitonin gene-related peptide receptor antagonist CGRP_(8-37) (3 nmol/kg) did not change the effects of AM. (3) Following intracarotid injection of NO precursor L-arginine (30mg/kg), the excitatory effect of AM was attenuated. The above results indicate that AM can excite spontaneous electrical activity of AP neurons, this effect is not mediated by calcitanin gene-related peptide receptor but may be attenuated by NO precursor L-arginine.
出处
《生理学报》
CAS
CSCD
北大核心
2003年第4期395-400,共6页
Acta Physiologica Sinica
关键词
肾上腺髓质素
最后区
自发放电单位
降钙素基因相关肽受体拮抗剂
L-精氨酸
adrenomedullin
area postrema
spontaneous single-units discharge
caicitonin gene-related peptide receptor antagonist
L-arginine